The invention relates to a cutting knife, in particular for cutting food according to the preamble of claim 1.
A cutting knife of this kind comprises a blade that is disposed to be rotatable about a rotation axis and a drive which is designed as an electric motor and comprises a revolving rotor and a stationary stator that cooperate for driving the blade and impart a rotational movement on the blade during operation of the cutting knife. A cutting knife of this kind serves for cutting food, in particular meat or fish.
A cutting knife known from EP 0 743 145 B1 is connected to an external electric drive via a flexible shaft transferring a torque, wherein the flexible shaft drives a mechanical gearing of the cutting knife, which engages via a toothed wheel in a circumferential toothing on a blade that is mounted rotatingly on the cutting knife. During operation of the cutting knife the flexible drive shaft imparts a rotational movement on the toothed wheel of the gearing, which imparts, by its engagement into the toothing on the rotatingly mounted blade, a rotational movement on the blade.
In a cutting knife known from EP 0 689 905 B1 the electric drive is transferred into the handle of the cutting knife and drives, via a drive shaft, a toothed wheel which engages in a circumferential toothing on a blade being mounted rotatingly on the cutting knife. The electrical drive in terms of an electric motor in the handle of the cutting knife is supplied with electric power by an external current supply unit in terms of a transformer, wherein the current supply unit is installed stationary and is connected via a cable of limited length with the cutting knife.
Various disadvantages arise from the arrangements of EP 0 689 905 B1 and EP 0 743 145 B1. The cutting knife of EP 0 689 905 B1 as well as of EP 0 743 145 B1 are, with regard to their construction, in particular with regard to the coupling of the electric drive with the blade, complex, prone to malfunction and service-intensive. In particular, for coupling the electric drive with the blade a gearing is required that engages, with a toothed wheel, in a toothing on the rotating blade and combs the toothing to drive the rotating blade. This causes the construction of the employed blade to be complicated, the blade requiring a toothing, which makes the manufacturing of the blade complicated and expensive. Second, the mounting of the blade and the coupling of the blade with the toothed wheel requires a permanent lubrication, which, when using the cutting knife for cutting food such as meat or fish, conventionally is done with vegetable oil, however hygienically is disadvantageous. Third, EP 0 689 905 B1 as well as EP 0 743 145 B1 require a coupling with an external drive or an external current supply unit, such that the cutting knife can be used only within a limited reach around the external drive and cannot be used in arbitrary locations, is limited during its operation in its reach and cannot be taken along arbitrarily.